This invention relates to an improvement in the design of lumbar support belts.
Participation in various occupations and sporting events such as manufacturing, moving and storage, heavy equipment operation, construction, weightlifting, motorcross and the like often places a considerable strain on the lower back. Efforts to alleviate back strain problems have been satisfactorily achieved through the use of lumbar (back) support belts of heavy, tightly woven fabric or traditional stiff leather. Such belts are tightened around the waist of the user with a wide central support portion abutting the lower back prior to engaging in activities where conditions are conducive to possible lower back strain. Such belts are commercially available in various widths and thicknesses to provide a suitable level of rigidity for supporting the user's lower back in his chosen activity.
Although current lumbar support belts are adequately designed to support the lower back, they do not provide a high degree of comfort. The user's skin covered by the wide central support portion of the belt often becomes hot, sweaty, and irritated during activity, and the skin at the edges of the belt may become chafed due to the belt's stiffness, all of which result in substantial discomfort to the user. Attempting to alleviate these drawbacks, some lumbar support belts have been provided with numerous holes in the central support portion for ventilation to reduce the heat and sweat developed during activity. However such ventilation is insufficient to provide the cooling required. If a greater density of holes were provided to increase the ventilation, the belts would lack sufficient structural stiffness to provide adequate support for the lower back.
Alexander et al. U.S. Pat. No. 5,070,866 discloses a semi-flexible back support belt with selective rigidity control. The belt comprises tightly-woven webbing formed of multiple layers or plies which are tied together by longitudinally extending binder yarns. The binder yarns provide a belt-rigidizing hinge arrangement within the webbing responsive to the application of longitudinally applied tensile loading on the belt. The necessity of a tight weave pattern prevents the belt from providing sufficient ventilation to minimize the sweat and heat created during its use. In order to provide selective rigidity control, the yarns cannot be fixed to each other but rather must be relatively movable with variations in the applied tension to allow for the hinged arrangement.
Gaylord U.S. Pat. No. 3,970,079 discloses a support binder utilizing an elastic woven textile fabric which has no ventilation capacity nor any stiffness apart from its plastic joints.
Raml U.S. Pat. No. 4,804,351 discloses a post-operative brassiere with an open-weave fabric that has some ventilation capacity. However, the open-weave fabric is a stretchable material which does not have the rigidity nor stiffness required for use as a back support belt.
To provide lumbar support, designers have also relied on a variety of schemes such as those shown in the following other U.S. Pat. Nos. 2,843,116; 2,541,487; 1,075,348.